Carl georg dahlgren and john hugo svensson



UNITED 'STATES PATENT OFFICE.

GTEBORG,

LATH E.

SPEGIFIGATION forming part of Letters Patent No. 469,813, dated March-1, 1892.

Application filed J'anuary 19, 1891. Serial N0. 378,300. (N0 model.)

T0 all whom it may corwern:

Be it known 1 ;hat we, CARL GEORG DAHL GREN and JOHN HUGO SVENSSON, bothsubjeets of the King of Sweden, residing at Gteborg, in the Kingdoxn ofSweden, have inventedacertain new and useful Improvegnent in Lathes,ofwhich the followlng is a speeifica-tion.

The objeet of this invention is. to enable prismaticor angular se ctionsto be turned in a lathe bymeans of simple meehanisrn.

Aeeording 120 this inven tion both the pieees 0f wood, metal, marble,stone, 01 ahy other material required t0 be turned, as he-reinafterdeseribed, and f0r which Ehe latl1e is made of suitable strength,respe'ctivelf7, (these pieees being hereinafter ealled the blank,) andalso the eutting-tool are rotated simultaneous1y with different ratlos0f veloeity, aeeording to the shape of section to be given to the piecewhen turned. By tl1is means sections having regular forms may be turned,said forms having (when the radius 0f the cuttingtool is equal to thegreat-est radius 0f the 0bject turne'd) a number of angles dependent onthe velocities aeeording to the formula 12 91:0 where n equals thenumber 0f angles, c the nurnber 0f blades on phe oireumference of thecutting-tool, 'v he rotary veloeioy of he tool, and v the rotaryveloeity of the blank. Thus a cutter having two eqnidistant blades will,if driven with a veloeity double that 0f the blank, Gut out afour-angled .figu're of seetion,1ahe faees 0f which are slightly convex.If driven with a veloeity treble that 0f the blank, lt Will cut out ahexagonal figure the faces of which will be slightly eoneave.

In the aecompanying drawings, Fignre 1 is a plan view of a lathe fittedwith the improvements. Fig. 2 is a diagram matic section show- Ing theturning of a four-angled figure. Fig. 3 is a similar view showing theturning of a hexagonal section.

In the drawings, A is the blank, which is fixed-on the live-spinclle ein the usual manne1. The live-spindle e drives the shaft 2 by means oftoothed wheels 2 e On the shaft 2 is the toothed wheel 2 whieh gea1swith the spherieal toothed wheel z, through whieh passes the shaft d,conneeted '00 rotate with be wheel z by means of a long feather dthereon moving in a keyway in the wheel, so

with usual adjustments parallel to and. perpendieular to bhe blank. Thejoint eonneeting the shafos d and a may be of any known construetion 0frocking joint, whereby the shaft d may revolve the shaft a at all times,whatever may be the relative an gular position of the axes 0f the shaftsduring the working 0f the xnachine. By replaeing t he one or other pairof wheels z 2 0r 2 2 by similar gearingwheels of different relativesizes the proportion between the veloeities of the spindle e and shaft dtherefore between the blank and the cutting-tool may be altered at will.

In cutting out a four-angled seetion the blade 0f the tool B meecs thesurfaee of the blank a1: the point y and, moving in the direetion of thearrow, will have reached Ehe point y, traveling through the angle x,while the blank has moved through the angle i%besubtends an angle ofsixty degrees, er twothirds of a right angle. The veloeities being astwo t0 0n e the other eutting-blade b 0f he tool will reach the point yexactly as the point z (where the former cut ended) arrives at saidpoint y. The cut; 2 y will then be made by tl1e blade b Similarly ehecut y y is made by the blade b, and the cut y y by the blade b, thuscompleting the figure.

The numerals I t0 VII and l to 7 illustrate relative simultaneouspositions.

T0 cut a hexagonal figure, the veloeity 0f the tool is t that of theblank as tl1ree to one.

Tl1e 13001 therefore passes throngh the angle w,

while tlie blank revolves through the angle% The am u will snbtend thesum of these angles, and (the figxe being six-sided) this snm willtherefore be sixty degrees, and the angle v will thus be forty-fivedegrees. The tool rotates throngh a distance of half its circunnferencewhile the blank moves through a sixth only. Therefore the blade b willmeet the point u at the position t and will cnt thepart u u. Similarlythe blade b will cnt u u and again u u, and the blade 12 will eut u uand u t. Similarly by use of diiferent proportions of velocities andequivalent adjustment of the angle subtendin g 'the overlapping part ofthe two circles other figures may be cut out.

It Will be understood that by approaehing the t-0ol to the blank so thatthe angle aforesaid is greater than its true Proportion the figure willsimply be ent to a smaller scale, while by setting ehe tool at a greaterdistance fron1 the blank the part necessary to complete a face ot thefigure will not be all rernoved, but a less portion will be rennoved,the eifeet being to leavea portion of the original circalarcirenmference between eaeh cut.

- We claim as our invention- In a lathe, the eombination ot' tl1elive-spin- .dle e, adapted t0 receive and revolve a blank,

CARL GEORG DAIILGREN. JOHN HUGO SVENSSON.

Witnesses:

CHARLES I-l. SHEPARD, HUGO ARWIDSSON.

